WO2023012929A1 - Aimant fritté à base de terres rares, procédé de production d'un aimant fritté à base de terres rares, rotor et machine rotative - Google Patents

Aimant fritté à base de terres rares, procédé de production d'un aimant fritté à base de terres rares, rotor et machine rotative Download PDF

Info

Publication number
WO2023012929A1
WO2023012929A1 PCT/JP2021/028943 JP2021028943W WO2023012929A1 WO 2023012929 A1 WO2023012929 A1 WO 2023012929A1 JP 2021028943 W JP2021028943 W JP 2021028943W WO 2023012929 A1 WO2023012929 A1 WO 2023012929A1
Authority
WO
WIPO (PCT)
Prior art keywords
rare earth
subphase
concentration
earth sintered
sintered magnet
Prior art date
Application number
PCT/JP2021/028943
Other languages
English (en)
Japanese (ja)
Inventor
亮人 岩▲崎▼
泰貴 中村
達也 北野
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to DE112021008057.1T priority Critical patent/DE112021008057T5/de
Priority to CN202180101117.7A priority patent/CN117751414A/zh
Priority to KR1020247002522A priority patent/KR20240028440A/ko
Priority to JP2021573953A priority patent/JP7130156B1/ja
Priority to PCT/JP2021/028943 priority patent/WO2023012929A1/fr
Publication of WO2023012929A1 publication Critical patent/WO2023012929A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/24—After-treatment of workpieces or articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/08—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of toothed articles, e.g. gear wheels; of cam discs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
    • H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • H01F41/0293—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/24—After-treatment of workpieces or articles
    • B22F2003/248—Thermal after-treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • B22F2009/041—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by mechanical alloying, e.g. blending, milling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/35—Iron
    • B22F2301/355—Rare Earth - Fe intermetallic alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/45—Rare earth metals, i.e. Sc, Y, Lanthanides (57-71)
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C2202/00—Physical properties
    • C22C2202/02—Magnetic

Definitions

  • the present disclosure relates to a rare earth sintered magnet, which is a permanent magnet obtained by sintering a material containing a rare earth element, a method for producing the rare earth sintered magnet, a rotor, and a rotating machine.
  • RTB system permanent magnets having a tetragonal R 2 T 14 B intermetallic compound as a main phase are known.
  • the element R is a rare earth element
  • the element T is a transition metal element such as Fe (iron) or Fe partially substituted with Co (cobalt)
  • B is boron.
  • RTB permanent magnets are used in various high-value-added parts, including industrial motors.
  • Nd--Fe--B based sintered magnets in which the element R is Nd (neodymium) are used in various parts due to their excellent magnetic properties.
  • industrial motors are often used in high-temperature environments exceeding 100°C. Attempts have been made to improve the magnetic force.
  • the production of Nd--Fe--B based sintered magnets has increased, and the consumption of heavy rare earth elements such as Nd, Dy and Tb (terbium) is increasing.
  • Nd and heavy rare earth elements are expensive and highly unevenly distributed, which poses a procurement risk. Therefore, as a measure to reduce the consumption of Nd and heavy rare earth elements, the element R includes Ce (cerium), La (lanthanum), Sm (samarium), Sc (scandium), Gd (gadolinium), Y (yttrium) and It is conceivable to use other rare earth elements such as Lu (lutetium).
  • Patent Document 1 a main phase having a tetragonal R 2 Fe 14 B crystal structure and having Fe and B as main constituent elements and at least one element selected from the group of Nd, La and Sm and a crystalline subphase containing at least one element selected from the group of Nd, La and Sm and O (oxygen) as a main constituent element.
  • La is segregated in the crystalline subphase
  • Sm is dispersed in the main phase and the crystalline subphase without segregation.
  • the above-described structural morphology suppresses deterioration of magnetic properties due to temperature rise.
  • Patent Document 2 a first phase containing a compound represented by RaTbX , and a grain boundary phase present at the grain boundary of the first phase and having a higher concentration of the element R than RaTbX , and a second phase consisting of a single crystal of a compound denoted by S c M d .
  • the element R is one or more rare earth elements including Nd
  • the element T is one or more transition metal elements including Fe
  • the element X is selected from B and C (carbon).
  • the element S is one or more rare earth elements including Sm
  • the element M is one or more transition metal elements including Co. According to the technique described in Patent Document 2, a rare earth magnet having sufficient magnetic properties even at high temperatures can be obtained.
  • Patent Document 3 discloses a first main phase composed of grains of an RTB alloy containing a light rare earth element as the element R and grains of an RTB alloy containing a heavy rare earth element as the element R.
  • RTB having a second main phase consisting of, a surface phase surrounding the surfaces of crystal grains constituting the first main phase and the second main phase, and a grain boundary alloy phase existing at the grain boundary triple point
  • the element T is Fe or part of Fe substituted with Co.
  • the heavy rare earth element concentration is lower in the first main phase and grain boundary alloy phase than in the second main phase and surface phase. According to the technique described in Patent Document 3, the coercive force can be effectively improved by using a rare earth element that provides a high coercive force.
  • the rare earth magnet alloy described in Patent Document 1 Sm is uniformly dispersed in the main phase and the sub phase in the rare earth magnet alloy, so it is possible to suppress the deterioration of the magnetic properties due to the temperature rise.
  • the second phase is composed of a single crystal, and there is no concentration difference in the elements present in the second phase. That is, although the second phase is distributed in the rare earth magnet, it has the same composition at any position and is formed by one type of compound having a uniform concentration distribution. Therefore, even the rare earth magnet described in Patent Document 2 does not have an optimum structure for improving magnetic properties at room temperature.
  • the RTB-based sintered magnet described in Patent Document 3 necessarily contains a heavy rare-earth element, so that a high coercive force can be obtained, but the residual magnetism required for industrial motors and the like can be obtained. There was a problem that a magnetic flux density could not be obtained and the magnetic properties were degraded. As described above, there has been a demand for a rare earth sintered magnet that achieves both improved magnetic properties at room temperature and suppression of deterioration in magnetic properties due to temperature rise.
  • the present disclosure has been made in view of the above, and it is possible to improve the magnetic properties at room temperature and suppress the deterioration of the magnetic properties due to temperature rise while suppressing the use of Nd and heavy rare earth elements.
  • An object is to obtain a rare earth sintered magnet.
  • the element M is one or more elements selected from the group of Cu, Al and Ga, and the general formula (Nd, La, Sm)-Fe -A rare earth sintered magnet satisfying BM, comprising a main phase containing crystal grains based on the R 2 Fe 14 B crystal structure and an oxide phase represented by (Nd, La, Sm)-O It has a crystalline first subphase containing a main component and a crystalline second subphase containing an oxide phase represented by (Nd, La)--O as a main component.
  • the concentration of Sm is higher in the first subphase than in the second subphase, and the concentration of the element M is higher in the second subphase than in the first subphase.
  • the present disclosure it is possible to improve the magnetic properties at room temperature and suppress the deterioration of the magnetic properties due to temperature rise while suppressing the use of Nd and heavy rare earth elements.
  • FIG. 1 is a diagram schematically showing an example of a sintered structure of a rare earth sintered magnet according to Embodiment 1.
  • Flowchart showing an example of the procedure of a method for manufacturing a rare earth magnet alloy according to Embodiment 2 FIG.
  • FIG. 11 is a diagram schematically showing the state of the method for producing a rare earth magnet alloy according to Embodiment 2; Flowchart showing an example of procedure of a method for manufacturing a rare earth sintered magnet according to Embodiment 2 Sectional view schematically showing an example of a configuration of a rotor equipped with rare earth sintered magnets according to Embodiment 3 Sectional view schematically showing an example of the configuration of a rotating machine according to Embodiment 4 Composition images obtained by analyzing cross sections of rare earth sintered magnets according to Examples 1 to 8 with FE-EPMA Elemental mapping of Nd obtained by analyzing cross sections of rare earth sintered magnets according to Examples 1 to 8 with FE-EPMA Elemental mapping of O obtained by analyzing cross sections of rare earth sintered magnets according to Examples 1 to 8 with FE-EPMA Elemental mapping of La obtained by analyzing cross sections of rare earth sintered magnets according to Examples 1 to 8 with FE-EPMA Elemental mapping of Sm obtained by analyzing cross sections of rare earth sintered magnets
  • a rare earth sintered magnet, a method for manufacturing a rare earth sintered magnet, a rotor, and a rotating machine according to embodiments of the present disclosure will be described in detail below with reference to the drawings.
  • FIG. 1 is a diagram schematically showing an example of the sintered structure of a rare earth sintered magnet according to Embodiment 1.
  • the permanent magnet according to Embodiment 1 is a rare earth sintered magnet 1 that satisfies the general formula (Nd, La, Sm)-Fe-BM and contains crystal grains based on the R 2 Fe 14 B crystal structure.
  • a rare earth sintered magnet 1 having a main phase 10 and a subphase 20 .
  • the subphase 20 consists of a crystalline first subphase 21 mainly composed of an oxide phase represented by (Nd, La, Sm)—O and an oxide phase represented by (Nd, La)—O. and a crystalline second subphase 22 containing as a main component.
  • Element M represents one or more elements selected from the group of Cu (copper), Al (aluminum) and Ga (gallium).
  • the main phase 10 has a tetragonal R 2 Fe 14 B crystal structure in which the elements R are Nd, La and Sm. That is, the main phase 10 has a composition formula of (Nd, La, Sm)2Fe14B .
  • the reason why the element R of the rare earth sintered magnet 1 having a tetragonal R 2 Fe 14 B crystal structure is a rare earth element consisting of Nd, La and Sm is that from the calculation results of the magnetic interaction energy using the molecular orbital method, This is because a practical rare earth sintered magnet 1 capable of suppressing deterioration in magnetic properties due to temperature rise can be obtained by using a composition in which La and Sm are added to Nd.
  • Nd is relatively diffused into the main phase 10 and the magnetocrystalline anisotropy of the main phase 10 is increased. can be done.
  • a pseudo-core-shell structure is formed in which the main phase 10 has portions with high magnetic anisotropy and portions with low magnetic anisotropy.
  • the effect of suppressing deterioration of magnetic properties due to temperature rise is further enhanced.
  • the amount of La and Sm added are too large, the amount of Nd, which is an element with a high magnetic anisotropy constant and saturation magnetic polarization, will decrease, resulting in a decrease in magnetic properties.
  • the composition ratios of are a, b, and c, respectively, it is preferable that a>(b+c).
  • the average grain size of the crystal grains of the main phase 10 is preferably 100 ⁇ m or less, and more preferably 0.1 ⁇ m or more and 50 ⁇ m or less in order to improve magnetic properties.
  • the crystalline subphase 20 is a generic term for the crystalline first subphase 21 and the crystalline second subphase 22 and exists between the main phases 10 .
  • the crystalline first subphase 21 is represented by (Nd, La, Sm)—O as described above
  • the crystalline second subphase 22 is represented by (Nd, La)—O as described above. be done.
  • (Nd, La, Sm) represented here means that part of Nd is replaced with La and Sm.
  • the first subphase 21 and the second subphase 22 may contain trace amounts of other components.
  • the second subphase 22 represented by (Nd, La)-O contains a very small amount of Sm.
  • the concentration of Sm is higher in the first subphase 21 than in the second subphase 22, and the concentration of element M is higher than that in the first subphase 21. , the second subphase 22 is higher.
  • Sm and element M are segregated in different subphases 20 . Since Sm exists in the first subphase 21 at a high concentration, it relatively diffuses Nd in the Nd-rich phase into the main phase 10 and improves the magnetocrystalline anisotropy of the main phase 10 . Furthermore, since Sm is also present in the crystal grains of the main phase 10, it is coupled in the same magnetization direction as Fe, which is a ferromagnetic material, thereby contributing to the improvement of residual magnetic flux density.
  • the element M Since the element M is present in the second subphase 22 at a high concentration, it forms a non-magnetic phase that magnetically separates the main phases 10 from each other and contributes to the improvement of the magnetic properties. Since Sm and the element M are present in each of the different subphases 20 at a high concentration, both the residual magnetic flux density and the coercive force can be improved.
  • the rare earth sintered magnet 1 there is a difference in concentration of La and Sm between the main phase 10 and the subphase 20, and the sum of the concentrations of La in the first subphase 21 and the second subphase 22 is , the La concentration in the main phase 10 or higher, and the sum of the Sm concentrations in the first subphase 21 and the second subphase 22 is higher than the Sm concentration in the main phase 10 .
  • the concentrations of La and Sm in the secondary phase 20 are greater than or equal to the concentrations of La and Sm in the main phase 10 .
  • La has a concentration difference between the first subphase 21 and the second subphase 22 , and the La concentration in the first subphase 21 is greater than or equal to the La concentration in the second subphase 22 .
  • the La concentration contained in the main phase 10 is X
  • the La concentration contained in the first subphase 21 is X1
  • the La concentration contained in the second subphase 22 is X2
  • the La concentration contained in the main phase 10 is X2.
  • the Sm concentration contained in the first subphase 21 is Y
  • the Sm concentration contained in the second subphase 22 is Y2
  • the Sm concentration contained in the second subphase 22 is Y2
  • the relationship of the following formula (1) is satisfied. .
  • La exists in a high concentration at the grain boundary during the manufacturing process, especially the heat treatment process, thereby relatively diffusing Nd into the main phase 10 .
  • the Nd of the main phase 10 is not consumed at the grain boundaries and the magnetocrystalline anisotropy is improved.
  • Sm is also present in the subphase 20, particularly in the first subphase 21, at a high concentration as compared to the main phase 10, Nd is relatively diffused into the main phase 10 similarly to La, thereby increasing magnetocrystalline anisotropy. improve.
  • the rare earth sintered magnet 1 according to Embodiment 1 may contain an additive element N for improving magnetic properties.
  • the additive element N is one selected from the group consisting of Co, Zr (zirconium), Ti (titanium), Pr (praseodymium), Nb (niobium), Dy, Tb, Mn (manganese), Gd and Ho (holmium). These are the above elements.
  • FIG. 2 is a diagram showing atomic sites in the tetragonal Nd 2 Fe 14 B crystal structure. It should be noted that the crystal structure shown in FIG. 2 is, for example, FIG. 1.
  • the site to be substituted is judged by the numerical value of the energy obtained by obtaining the stabilization energy due to substitution by band calculation and molecular field approximation of the Heisenberg model. (Reference 1) JFHerbst et al. “Relationships between crystal structure and magnetic properties in Nd2Fe14B ”. PHYSICAL REVIEW B. 1984, Vol.29, No.7 , p.4176-4178.
  • the stabilization energy in La is obtained from the energy difference between (Nd7La1)Fe56B4 + Nd and Nd8 ( Fe55La1 ) B4 +Fe using a Nd8Fe56B4 crystal cell . be able to.
  • This calculation assumes that the lattice constant in the tetragonal R 2 Fe 14 B crystal structure does not change with the difference in atomic radius when La replaces the original atom.
  • Table 1 shows the stabilization energy of La at each substitution site when the environmental temperature is changed.
  • the stable substitution site of La is the Nd(f) site at temperatures of 1000K or higher, and the Fe(c) site at temperatures of 293K and 500K.
  • the rare earth sintered magnet 1 according to Embodiment 1 is melted by heating the raw material of the rare earth sintered magnet 1 to a temperature of 1000K or higher, and then rapidly cooled. For this reason, it is considered that the raw material of the rare earth sintered magnet 1 is maintained at a temperature of 1000K or higher, that is, 727°C or higher, preferably about 1300K, that is, 1027°C.
  • La is considered to be substituted with Nd(f) site or Nd(g) site.
  • the Nd(g) site is also cited as a candidate for the La substitution site.
  • the temperature was 1000K or more at the time of sintering, the temperature was reduced to that shown in Table 1 by going through the primary aging process, the secondary aging process, and the cooling process.
  • the described Fe(c) sites are retained in the energetically stable temperature range. In other words, La substitution at the Nd site of the main phase 10 is kept in an unstable energy state.
  • the stabilization energy of Sm can be obtained from the energy difference between (Nd7Sm1)Fe56B4+Nd and Nd8 ( Fe55Sm1 ) B4 + Fe . It is the same as in the case of La that the lattice constant in the tetragonal R 2 Fe 14 B crystal structure does not change due to atom substitution.
  • Table 2 is a table showing the stabilization energy of Sm at each substitution site when the environmental temperature is changed.
  • the stable substitution site of Sm is the Nd(g) site at any temperature.
  • Sm is also considered to be preferentially substituted with the energetically stable Nd(g) site, but substitution with the Nd(f) site, which has a small energy difference among the substitution sites of Sm, is also possible.
  • the replacement of the main phase 10 with the Nd(g) site is the most stable in terms of energy.
  • some Sm is also released from the Nd site of the main phase 10 together with La. , segregates into the subphase 20 .
  • the sum of the Sm concentrations in the first subphase 21 and the second subphase 22 is equal to or higher than the Sm concentration in the main phase 10 .
  • La and Sm can be said to segregate in the subphase 20 .
  • the La concentration is the same as the Sm concentration, and the La concentration in the first subphase 21 is equal to or higher than the La concentration in the second subphase 22. You can say that.
  • La and Sm are compared, it can be seen that La, which is held in a temperature range in an unstable energy state, is overwhelmingly more likely to segregate into the subphase 20 from an energetic point of view.
  • La has a higher segregation ratio to the subphase 20 than La and Sm present in the rare earth sintered magnet 1. That is, it means that the relationship of the above formula (1) is satisfied.
  • the element M that is, elements such as Cu, Al and Ga, which form non-magnetic phases at grain boundaries and contribute to increasing the coercive force, originally exist in the subphase 20 .
  • the element M is mainly present in the subphase 20 different from La and Sm. . That is, each element does not exist uniformly, but the concentration of the element M including Cu, Al, and Ga is higher in the second subphase 22 than in the first subphase 21 .
  • the first subphase 21 has a higher Sm concentration than the second subphase 22, and the second subphase 22 has a higher element M concentration than the first subphase 21.
  • a rare earth sintered magnet 1 having a feature that Sm and the element M are different from each other in subphases 20 with high concentrations is obtained.
  • the element M is one or more elements selected from the group of Cu, Al and Ga, and the general formula (Nd, La, Sm)-Fe- A rare earth sintered magnet 1 satisfying BM, comprising a main phase 10 containing crystal grains based on an R 2 Fe 14 B crystal structure, and an oxide phase represented by (Nd, La, Sm)—O and a crystalline second subphase 22 mainly composed of an oxide phase represented by (Nd, La)--O.
  • the concentration of Sm is higher in the first subphase 21 than in the second subphase 22, and the concentration of the element M is higher in the first subphase 22.
  • the height of the second subphase 22 was set higher than that of the phase 21 . That is, the concentration of Sm and the concentration of the element M in the subphase 20 are made different. As a result, since Sm exists in the first subphase 21 at a high concentration, it relatively diffuses Nd into the main phase 10 and improves the magnetocrystalline anisotropy of the main phase 10 . Furthermore, since Sm is also present in the crystal grains of the main phase 10, it is coupled in the same magnetization direction as Fe, which is a ferromagnetic material, thereby contributing to the improvement of residual magnetic flux density.
  • the element M Since the element M is present in the second subphase 22 at a high concentration, it forms a non-magnetic phase that magnetically separates the main phases 10 from each other and contributes to the improvement of the magnetic properties. Since Sm and the element M are present in different subphases 20 at high concentrations, both the residual magnetic flux density and the coercive force can be improved.
  • the main phase 10 has a tetragonal R 2 Fe 14 B crystal structure in which the elements R are Nd, La and Sm, the rare earth sintered magnet 1 can suppress a decrease in magnetic properties due to temperature rise. becomes.
  • the rare earth sintered magnets that satisfy Nd--Fe--B the use of Nd and heavy rare earth elements is suppressed, the magnetic properties are improved at room temperature, the deterioration of magnetic properties due to temperature rise is suppressed, can be obtained.
  • Embodiment 2 the method of manufacturing the rare earth sintered magnet 1 described in Embodiment 1 will be described. A method of manufacturing the magnet 1 and a method of manufacturing the magnet 1 will be separately described.
  • FIG. 3 is a flow chart showing an example of the procedure of a method for manufacturing a rare earth magnet alloy according to Embodiment 2.
  • FIG. 4A and 4B are diagrams schematically showing a method for manufacturing a rare earth magnet alloy according to Embodiment 2.
  • FIG. 4A and 4B are diagrams schematically showing a method for manufacturing a rare earth magnet alloy according to Embodiment 2.
  • the method of manufacturing a rare earth magnet alloy includes a melting step (step S1) of heating and melting a raw material of a rare earth magnet alloy containing elements constituting the rare earth sintered magnet 1 to a temperature of 1000K or higher. ), a primary cooling step (step S2) of cooling the raw material in a molten state on a rotating rotating body to obtain a solidified alloy, and a secondary cooling step (step S3) of further cooling the solidified alloy in a container. ) and including.
  • a melting step S1 of heating and melting a raw material of a rare earth magnet alloy containing elements constituting the rare earth sintered magnet 1 to a temperature of 1000K or higher.
  • a primary cooling step step S2 of cooling the raw material in a molten state on a rotating rotating body to obtain a solidified alloy
  • a secondary cooling step step S3 of further cooling the solidified alloy in a container.
  • step S1 the raw material of the rare earth magnet alloy is heated to a temperature of 1000 K or higher in the crucible 31 in an atmosphere containing an inert gas such as Ar (argon) or in a vacuum. to melt.
  • an inert gas such as Ar (argon) or in a vacuum.
  • a molten alloy 32 in which rare earth magnet alloy is melted is prepared.
  • a combination of Nd, La, Sm, Fe, B, and one or more elements M selected from the group of Al, Cu and Ga can be used.
  • one or more elements selected from the group consisting of Co, Zr, Ti, Pr, Nb, Dy, Tb, Mn, Gd and Ho as the additional element N may be included in the raw material.
  • the molten alloy 32 prepared in the melting step is poured into a tundish 33, followed by a rotating body that rotates in the direction of the arrow. Cast over single roll 34 .
  • the molten alloy 32 is rapidly cooled on the single roll 34 and a solidified alloy 35 thinner than the ingot alloy is prepared on the single roll 34 from the molten alloy 32 .
  • the single roll 34 is used as the rotating rotating body, but it is not limited to this, and it may be brought into contact with a twin roll, a rotating disk, a rotating cylindrical mold, or the like, and rapidly cooled.
  • the cooling rate in the primary cooling step is preferably 10°C/second or more and 10 7 °C/second or less, and 10 3 °C/second or more and 10 4 °C. / second or less is more preferable.
  • the thickness of the solidified alloy 35 is in the range of 0.03 mm or more and 10 mm or less.
  • the molten alloy 32 begins to solidify from the portion in contact with the single roll 34, and crystals grow in the thickness direction from the contact surface with the single roll 34 in the form of columns or needles.
  • the thin solidified alloy 35 prepared in the primary cooling step is placed in a tray container 36 and cooled.
  • the solidified alloy 35 having a small thickness is crushed when it enters the tray container 36 and becomes a scaly rare earth magnet alloy 37 and is cooled.
  • the ribbon-shaped rare earth magnet alloy 37 may be obtained, and is not limited to the scale-shaped.
  • the cooling rate in the secondary cooling step is preferably 10 -2 ° C./sec or more and 10 5 ° C./sec or less. More preferably, the temperature is 10 -1 °C/sec or more and 10 2 °C/sec or less.
  • the rare earth magnet alloy 37 obtained through these steps has a minor axis size of 3 ⁇ m or more and 10 ⁇ m or less and a major axis size of 10 ⁇ m or more and 300 ⁇ m or less (Nd, La, Sm)—Fe—B crystal phase. and a crystalline subphase 20 of an oxide represented by (Nd, La, Sm)-O.
  • the oxide crystalline subphase 20 denoted (Nd,La,Sm)--O will be referred to as the (Nd,La,Sm)--O phase.
  • the (Nd, La, Sm)--O phase is a non-magnetic phase composed of an oxide with a relatively high concentration of rare earth elements.
  • the thickness of the (Nd, La, Sm)—O phase corresponds to the width of the grain boundary and is 10 ⁇ m or less. Since the rare earth magnet alloy 37 manufactured by the above manufacturing method has undergone a rapid cooling process, it has a finer structure and a grain size than the rare earth magnet alloy obtained by the mold casting method. is small.
  • FIG. 5 is a flow chart showing an example of the procedure of a method for manufacturing a rare earth sintered magnet according to Embodiment 2.
  • the method of manufacturing the rare earth sintered magnet 1 includes a pulverizing step (step S21) of pulverizing the rare earth magnet alloy 37 satisfying (Nd, La, Sm)-Fe-BM, and A forming step (step S22) of preparing a compact by compacting the powder of the rare earth magnet alloy 37, a sintering step (step S23) of obtaining a sintered body by sintering the compact, and a sintered compact and an aging step (step S24) of aging and a cooling step (step S25) of cooling the aged sintered body.
  • the rare earth magnet alloy 37 manufactured according to the method for manufacturing the rare earth magnet alloy 37 of FIG. A rare earth magnet alloy 37 having a phase and is pulverized to obtain a rare earth magnet alloy powder having a particle size of 200 ⁇ m or less, preferably 0.5 ⁇ m or more and 100 ⁇ m or less.
  • the rare earth magnet alloy 37 pulverized here contains one or more elements M selected from the group of Al, Cu and Ga, as described above. Pulverization of the rare earth magnet alloy 37 is performed using, for example, an agate mortar, stamp mill, jaw crusher, or jet mill.
  • the rare earth magnet alloy 37 when reducing the particle size of the powder, it is preferable to pulverize the rare earth magnet alloy 37 in an atmosphere containing an inert gas.
  • By pulverizing the rare earth magnet alloy 37 in an atmosphere containing an inert gas it is possible to suppress oxygen from being mixed into the powder.
  • pulverization of the rare earth magnet alloy 37 may be performed in the air.
  • the powder of the rare earth magnet alloy 37 is compression-molded in a mold to which a magnetic field is applied to prepare a compact.
  • the applied magnetic field can be 2T, for example. It should be noted that the molding may be performed without applying a magnetic field instead of in a magnetic field.
  • the compression-molded body is held at a sintering temperature in the range of 900° C. to 1300° C. for a time in the range of 0.1 hour to 10 hours, thereby sintering prepare the body; Sintering is preferably carried out in an atmosphere containing an inert gas or in a vacuum in order to suppress oxidation. Sintering may be performed while applying a magnetic field.
  • the sintering step may be added with a step of hot working or aging treatment to improve magnetic properties, that is, to make magnetic field anisotropic or to improve coercive force.
  • a step of infiltrating a compound containing Cu, Al, a heavy rare earth element, or the like into the grain boundaries, which are the boundaries between the main phases 10, may be added.
  • the aging process of step S24 includes a first aging process of step S24-1 and a second aging process of step S24-2.
  • the conditions for the primary aging step in step S24-1 are that the sintered body is subjected to the primary aging temperature which is lower than the sintering temperature, specifically at a temperature within the range of 700° C. or higher and lower than 900° C.
  • the sintered body is held within the range of 0.1 hour or more and 10 hours or less.
  • the condition of the second aging step in step S24-2 is the second aging temperature which is lower than the first aging temperature after the first aging step, specifically in the range of 450°C or more and less than 700°C.
  • the sintered body is held at a temperature within the range of 0.1 hour or more and 10 hours or less.
  • the sintered body is cooled at a temperature lower than the secondary aging temperature, specifically at a temperature within the range of 200° C. or more and less than 450° C. for 0.1 hour or more and 5 hours or less. Hold. Thereafter, the rare earth sintered magnet 1 is completed by cooling to room temperature.
  • the concentration of Sm is higher in the first subphase 21 than in the second subphase 22 by controlling the temperature and time as described above.
  • a rare earth sintered magnet 1 is manufactured in which the concentration of one or more elements M selected from the group of Cu, Al and Ga is higher in the second subphase 22 than in the first subphase 21. be able to. That is, in the aging step and the cooling step, the oxide phase represented by (Nd, La, Sm)—O is the main component from the (Nd, La, Sm)—O phase, depending on the concentration of the element M, for example. and a crystalline second subphase 22 mainly composed of an oxide phase represented by (Nd, La)-O.
  • the second subphase 22 may contain a small amount of Sm.
  • the rare earth magnet alloy powder 37 having the (Nd, La, Sm)--Fe--B crystal phase and the (Nd, La, Sm)--O phase is pulverized to form a rare earth magnet alloy powder.
  • the sintered body is aged and cooled to produce the rare earth sintered magnet 1 .
  • rare earth sintered magnet 1 according to Embodiment 1 can be manufactured.
  • the sintered body is heated at a temperature lower than the sintering temperature, specifically at a first aging temperature in the range of 700° C. or more and less than 900° C. for 0.1 hour or more and 10 hours or less.
  • the sintered body is held within the range of , and in the second aging step, after the first aging step, at a second aging temperature lower than the first aging temperature, specifically 450 ° C. or higher and lower than 700 ° C.
  • the sintered body is held at a temperature within the range of 0.1 hour or more and 10 hours or less, and in the cooling step, at a temperature lower than the secondary aging temperature, specifically 200 ° C. or higher and 450 ° C.
  • the sintered body is held at a temperature within the range of less than 0.1 hour or more and 5 hours or less, and cooled to room temperature.
  • the concentration of Sm is higher in the first subphase 21 than in the second subphase 22, and the concentration of one or more elements M selected from the group of Cu, Al and Ga is A rare earth sintered magnet 1 in which the second subphase 22 is higher than the first subphase 21 can be produced.
  • the sum of the La concentrations in the first subphase 21 and the second subphase 22 becomes equal to or higher than the La concentration in the main phase 10, and the Sm concentration in the first subphase 21 and the second subphase 22 is equal to or higher than the concentration of Sm in the main phase 10, and the concentration of La in the first subphase 21 is equal to or higher than the concentration of La in the second subphase 22.
  • the La concentration and Sm concentration contained in the main phase 10 the La concentration and Sm concentration contained in the first subphase 21, and the La concentration and Sm concentration contained in the second subphase 22 satisfy the above formula (1).
  • a rare earth sintered magnet 1 can be produced.
  • FIG. 6 is a cross-sectional view schematically showing an example of the configuration of a rotor equipped with rare earth sintered magnets according to Embodiment 3.
  • FIG. 6 shows a cross section of the rotor 100 in a direction perpendicular to the rotation axis RA.
  • the rotor 100 is rotatable around the rotation axis RA.
  • the rotor 100 includes a rotor core 101 and rare earth sintered magnets 1 inserted into magnet insertion holes 102 provided in the rotor core 101 along the circumferential direction of the rotor 100 .
  • rare earth sintered magnets 1 are used in FIG. 6 , the number of rare earth sintered magnets 1 is not limited to this, and may be changed according to the design of rotor 100 .
  • the rotor core 101 is formed by laminating a plurality of disk-shaped electromagnetic steel sheets in the axial direction of the rotation shaft RA.
  • the rare earth sintered magnet 1 has the structure described in the first embodiment and is manufactured according to the manufacturing method described in the second embodiment.
  • Four rare earth sintered magnets 1 are inserted into corresponding magnet insertion holes 102 .
  • the four rare earth sintered magnets 1 are each magnetized such that the magnetic poles of the rare earth sintered magnets 1 on the radially outer side of the rotor 100 are different from adjacent rare earth sintered magnets 1 .
  • the rotor 100 according to Embodiment 3 includes the rare earth sintered magnet 1 according to Embodiment 1, which can improve the magnetic properties at room temperature and suppress the deterioration of the magnetic properties due to temperature rise. .
  • the rare earth sintered magnet 1 is capable of suppressing deterioration in magnetic properties due to temperature rise while maintaining high residual magnetic flux density and coercive force. Also, the deterioration of the magnetic properties is suppressed. As a result, the operation of the rotor 100 can be stabilized even in a high temperature environment exceeding 100.degree.
  • FIG. 7 is a cross-sectional view schematically showing an example of the configuration of a rotating machine according to Embodiment 4.
  • FIG. 7 shows a cross section of the rotor 100 in a direction perpendicular to the rotation axis RA.
  • Rotating machine 120 includes rotor 100 described in Embodiment 3, which is rotatable about rotation axis RA, and annular stator 130 provided coaxially with rotor 100 and arranged to face rotor 100. , provided.
  • the stator 130 is formed by laminating a plurality of electromagnetic steel plates in the axial direction of the rotation shaft RA.
  • the configuration of the stator 130 is not limited to this, and an existing configuration can be adopted.
  • Stator 130 is provided with teeth 131 protruding toward rotor 100 along the inner surface of stator 130 .
  • Windings 132 are provided on the teeth 131 .
  • the winding method of the winding 132 is not limited to concentrated winding, and may be distributed winding.
  • the rotor 100 in the rotating machine 120 may have two or more magnetic poles, that is, two or more rare earth sintered magnets 1 .
  • the magnet-embedded rotor 100 is used, but a surface magnet type in which the rare-earth sintered magnets 1 are fixed to the outer periphery with an adhesive may be used.
  • the rotating machine 120 according to Embodiment 4 includes the rare earth sintered magnet 1 according to Embodiment 1, which can improve the magnetic properties at room temperature and suppress the deterioration of the magnetic properties due to temperature rise. .
  • the rare earth sintered magnet 1 is capable of suppressing deterioration in magnetic properties due to temperature rise while maintaining high residual magnetic flux density and coercive force. Also, the deterioration of the magnetic properties is suppressed. As a result, it is possible to stably drive the rotor 100 and stabilize the operation of the rotating machine 120 even in a high temperature environment exceeding 100°C.
  • the details of the rare earth sintered magnet 1 of the present disclosure will be described below with reference to examples and comparative examples.
  • Examples 1 to 8 and Comparative Examples 1 to 6 samples represented by R—Fe—BMN of a plurality of rare earth magnet alloys 37 having different compositions of the main phase 10 were used, and the samples shown in Embodiment 2 were used.
  • a rare earth sintered magnet 1 is manufactured by the method described.
  • the portion of element R is changed.
  • the rare earth sintered magnet 1 is manufactured using the rare earth magnet alloy 37 in which the contents of Nd, La and Sm in the element R are changed.
  • the rare earth magnet alloy 37 that does not contain the additive element N and that contains one or more elements M selected from the group of Cu, Al and Ga is used.
  • the rare earth magnet added with the element M and one or more additional elements N selected from the group consisting of Co, Zr, Ti, Pr, Nb, Dy, Tb, Mn, Gd and Ho Alloy 37 is used.
  • Comparative Examples 1 and 3 use the rare earth magnet alloy 37 in which the element R is Nd. However, in Comparative Example 1, the element M and the additive element N are not included, and in Comparative Example 3, the additive element N is not included.
  • Comparative Examples 2 and 4 the rare earth magnet alloy 37 containing Nd as the element R and Dy, which is a heavy rare earth element, is used. However, Comparative Example 2 does not contain the element M and the additive element N, and Comparative Example 4 does not contain the additive element N.
  • Table 3 is a table showing the general formula of rare earth sintered magnets according to Examples and Comparative Examples, the content of elements constituting the element R, the analysis results of the morphology of the structure, and the determination results of the magnetic properties.
  • Table 3 shows the general formula of the main phase 10 of each sample, which is the rare earth sintered magnet 1 of Examples 1 to 8 and Comparative Examples 1 to 6. Moreover, Table 3 shows only the presence or absence of the addition of the element M and the additional element N. In Examples 1 to 8 and Comparative Examples 3 and 4, the case where the element M includes Cu, Al and Ga is taken as an example.
  • the morphology of the rare earth sintered magnet 1 is determined by elemental analysis using a scanning electron microscope (SEM) and an electron probe micro analyzer (EPMA).
  • SEM scanning electron microscope
  • EPMA electron probe micro analyzer
  • a field emission electron probe microanalyzer manufactured by JEOL Ltd., product name: JXA-8530F is used as the SEM and EPMA.
  • the conditions for elemental analysis were an acceleration voltage of 15.0 kV, an irradiation current of 22.71 nA, an irradiation time of 130 ms, a pixel count of 512 pixels ⁇ 512 pixels, a magnification of 5000 times, and an integration The number of times is 1.
  • Magnetic properties are evaluated by measuring the coercive force of a plurality of samples using a pulse excitation BH tracer.
  • the maximum magnetic field applied by the BH tracer is 6 T or more at which the rare earth sintered magnet 1 is completely magnetized.
  • a DC type BH tracer In addition to the pulse excitation type BH tracer, if it is possible to generate a maximum applied magnetic field of 6 T or more, it is also called a DC type BH tracer, a DC self-recording magnetometer, a vibrating sample magnetometer (VSM), a magnetic property A measuring device (Magnetic Property Measurement System: MPMS), a physical property measuring device (Physical Property Measurement System: PPMS), etc. may be used. Measurement is performed in an atmosphere containing an inert gas such as nitrogen. The magnetic properties of each sample are measured at a first measurement temperature T1 and a second measurement temperature T2, which are different from each other.
  • VSM vibrating sample magnetometer
  • MPMS Magnetic Property Measurement System
  • PPMS Physical Property Measurement System
  • the temperature coefficient ⁇ [%/°C] of the residual magnetic flux density is the difference between the residual magnetic flux density at the first measurement temperature T1 and the residual magnetic flux density at the second measurement temperature T2, and the residual magnetic flux density at the first measurement temperature T1 is divided by the temperature difference (T2-T1).
  • the coercive force temperature coefficient ⁇ [%/°C] is the difference between the coercive force at the first measured temperature T1 and the coercive force at the second measured temperature T2, and the coercive force at the first measured temperature T1. It is a value obtained by dividing the ratio by the temperature difference (T2-T1). Therefore, the smaller the absolute values
  • FIG. 8 is a composition image obtained by analyzing the cross section of the rare earth sintered magnets according to Examples 1 to 8 with a Field Emission-Electron Probe Micro Analyzer (FE-EPMA).
  • 9 to 15 are elemental mappings obtained by analyzing cross sections of rare earth sintered magnets according to Examples 1 to 8 with FE-EPMA.
  • 9 is the elemental mapping of Nd
  • FIG. 10 is the elemental mapping of O
  • FIG. 11 is the elemental mapping of La
  • FIG. 12 is the elemental mapping of Sm
  • FIG. 14 is an elemental mapping of Al
  • FIG. 15 is an elemental mapping of Ga.
  • FIGS. 8 to 15 show representative examples among Examples 1 to 8. Further, the same reference numerals are assigned to the same components as in FIG.
  • the main phase 10 which is a crystal grain based on the R 2 Fe 14 B crystal structure, (Nd, La, Sm)—O
  • a crystalline first subphase 21 whose main component is an oxide phase represented by and a crystalline second subphase 22 whose main component is an oxide phase represented by (Nd, La)-O
  • the first subphase 21 has a higher Sm concentration than the second subphase 22 .
  • the concentration of one or more elements M selected from the group of Cu, Al and Ga is higher in the second subphase 22 than in the first subphase 21. can be confirmed.
  • the sum of the La concentrations in the first subphase 21 and the second subphase 22 is equal to or higher than the La concentration in the main phase 10, and the second It can be confirmed that the sum of the Sm concentrations in the first subphase 21 and the second subphase 22 is greater than or equal to the Sm concentration in the main phase 10 . Furthermore, it can be confirmed that the concentration of La in the first subphase 21 is equal to or higher than the concentration of La in the second subphase 22 .
  • the La concentration contained in the main phase 10, the first subphase 21 and the second subphase 22 and the Sm concentration contained in the main phase 10, the first subphase 21 and the second subphase 22 are defined by FE- From the intensity ratio of elemental mapping obtained by EPMA analysis, the La concentration contained in the main phase 10, the first subphase 21 and the second subphase 22, the main phase 10, the first subphase 21 and the second subphase It can be confirmed that the relationship between the Sm concentration contained in the phase 22 and the above formula (1) is satisfied.
  • the shape of each sample for magnetic measurement is a block shape with length, width and height of 7 mm.
  • the first measured temperature T1 is 23°C and the second measured temperature T2 is 200°C.
  • 23°C is room temperature.
  • 200° C. is a temperature that can occur as an environment during operation of motors for automobiles and industrial motors.
  • the residual magnetic flux density and coercive force of each sample according to Examples 1 to 8 and Comparative Examples 2 to 6 are compared with Comparative Example 1. If the residual magnetic flux density and coercive force values of each sample at 23 ° C. show values within 1%, which is considered to be a measurement error compared to the values in Comparative Example 1, it is judged to be "equivalent”, If the value is 1% or higher, it is determined as “good”, and if the value is 1% or less, it is determined as "poor".
  • the temperature coefficient ⁇ of the residual magnetic flux density is calculated using the residual magnetic flux density at the first measurement temperature T1 of 23°C and the residual magnetic flux density at the second measurement temperature T2 of 200°C.
  • the coercive force temperature coefficient ⁇ is calculated using the coercive force at the first measurement temperature T1 of 23°C and the coercive force at the second measurement temperature T2 of 200°C.
  • the temperature coefficient of residual magnetic flux density and the temperature coefficient of coercive force in each sample according to Examples 1-8 and Comparative Examples 2-6 are determined in comparison with Comparative Example 1.
  • Table 3 shows the determination results of the residual magnetic flux density, the coercive force, the temperature coefficient of the residual magnetic flux density, and the temperature coefficient of the coercive force.
  • Comparative Example 1 is a sample of rare earth sintered magnet 1 produced according to the production method of Embodiment 2 using Nd, Fe and FeB as raw materials so as to form Nd--Fe--B. Observing the morphology of the structure of this sample according to the method described above, it cannot be confirmed that the concentration of Sm is higher in the first subphase 21 than in the second subphase 22 because Sm is not added. Furthermore, since the element M is not added either, it cannot be confirmed that the concentration of the element M is higher in the second subphase 22 than in the first subphase 21 . Further, when the magnetic properties of this sample were evaluated according to the method described above, the residual magnetic flux density was 1.3 T and the coercive force was 1000 kA/m. The temperature coefficients of remanence and coercivity are
  • 0.191%/°C and
  • 0.460%/°C, respectively. These values of Comparative Example 1 are used as a reference.
  • Comparative Example 2 is a sample of rare earth sintered magnet 1 produced according to the production method of Embodiment 2 using Nd, Dy, Fe and FeB as raw materials so as to form (Nd, Dy)--Fe--B. . Observing the morphology of the structure of this sample according to the method described above, it cannot be confirmed that the concentration of Sm is higher in the first subphase 21 than in the second subphase 22 because Sm is not added. Furthermore, since the element M is not added either, it cannot be confirmed that the concentration of the element M is higher in the second subphase 22 than in the first subphase 21 .
  • Comparative Example 3 is a sample of rare earth sintered magnet 1 produced according to the production method of Embodiment 2 using Nd, Fe and FeB, and element M as raw materials so as to form Nd--Fe--BM. .
  • Observation of the morphology of the structure of this sample according to the method described above reveals that the concentration of Sm is higher in the first subphase 21 than in the second subphase 22 because Sm is not added.
  • the element M is added, the first subphase 21 and the second subphase 22 are not formed due to the absence of Sm, and the concentration of the element M is lower than the first subphase 21. It cannot be confirmed that the two-subphase 22 is higher.
  • Comparative Example 4 is a sintered rare earth element produced according to the production method of Embodiment 2 using Nd, Dy, Fe and FeB as raw materials to form (Nd, Dy)-Fe-BM, and further using element M as raw materials. It is a sample of Magnet 1. Observation of the morphology of the structure of this sample according to the method described above reveals that the concentration of Sm is higher in the first subphase 21 than in the second subphase 22 because Sm is not added. In addition, although the element M is added, the first subphase 21 and the second subphase 22 are not formed due to the absence of Sm, and the concentration of the element M is lower than the first subphase 21. It cannot be confirmed that the two-subphase 22 is higher.
  • Comparative Example 5 is a rare earth sintered magnet 1 produced according to the production method of Embodiment 2 using Nd, La, Sm, Fe and FeB as raw materials so as to form (Nd, La, Sm)-Fe-B. is a sample. Observing the structure of this sample according to the method described above, Sm was added but M was not added, so two types of subphases 20, a first subphase 21 and a second subphase 22, were confirmed. Moreover, the Sm concentration is uniformly distributed in the main phase 10 and the subphase 20 . Furthermore, since the two types of subphases 20 do not exist, it cannot be confirmed that the first subphase 21 is higher than the second subphase 22 .
  • the concentration of the element M is higher in the second subphase 22 than in the first subphase 21 .
  • the residual magnetic flux density was "bad”
  • the coercive force was "bad”
  • the temperature coefficient of the residual magnetic flux density was "good”
  • the coercive force temperature coefficient was "Good”. This is because the presence of La and Sm in the main phase 10 or the subphase 20 results in good temperature coefficients of the magnetic properties, but the two types of subphases 20 do not exist and these subphases 20 do not exist.
  • the result reflects that the concentration of Sm and the concentration of the element M in the phase 20 are not suitable structure morphology.
  • Comparative Example 6 contains Nd, La, Sm, Fe and FeB, and further Co, Zr, Ti, Pr, Nb, Dy, Tb, Mn so as to become (Nd, La, Sm)-Fe-B-N , Gd, and Ho, and is a sample of a rare earth sintered magnet 1 manufactured according to the manufacturing method of Embodiment 2 using as a raw material one or more additive elements N selected from the group of Gd and Ho. Observation of the morphology of the structure of this sample according to the method described above reveals that although Sm is added, the element M is not added. Moreover, the Sm concentration is uniformly distributed in the main phase 10 and the subphase 20, which cannot be confirmed.
  • the two types of subphases 20 do not exist, it cannot be confirmed that the first subphase 21 is higher than the second subphase 22 . Furthermore, since the element M is not added either, it cannot be confirmed that the concentration of the element M is higher in the second subphase 22 than in the first subphase 21 .
  • the residual magnetic flux density was "good”
  • the coercive force was "bad”
  • the temperature coefficient of the residual magnetic flux density was "good”
  • the coercive force temperature coefficient was "Good”. Due to the presence of La and Sm in the main phase 10 or the subphase 20, good temperature coefficients of magnetic properties are obtained.
  • the magnetic flux density is improved due to the effect of the additive element N such as Co, which is a magnetic material.
  • the results reflect the absence of the two types of subphases 20 and the fact that the concentrations of Sm and the element M in these subphases 20 are not appropriate structural forms.
  • Nd, La, Sm, Fe and FeB are used as raw materials so as to form (Nd, La, Sm)-Fe-B-M, and the element M is used as the raw material for the manufacturing method of the second embodiment.
  • It is a sample of the rare earth sintered magnet 1 produced according to. Observation of the structural morphology of these samples according to the method described above confirms that the Sm concentration is higher in the first subphase 21 than in the second subphase 22 . Furthermore, it can be confirmed that the concentration of the element M is higher in the second subphase 22 than in the first subphase 21 .
  • the residual magnetic flux density is “good”
  • the coercive force is “good”
  • the temperature coefficient of the residual magnetic flux density is “good”
  • the temperature coefficient of the coercive force is “good”.
  • Example 8 is an embodiment using Nd, La, Sm, Fe and FeB, an element M, and an additive element N as raw materials so as to form (Nd, La, Sm)-Fe-BMN.
  • 2 is a sample of a rare earth sintered magnet 1 produced according to the production method of No. 2. Observation of the morphology of the structure of this sample according to the method described above confirms that the concentration of Sm is higher in the first subphase 21 than in the second subphase 22 . Furthermore, it can be confirmed that the concentration of the element M is higher in the second subphase 22 than in the first subphase 21 .
  • the residual magnetic flux density is "good”
  • the coercive force is “good”
  • the temperature coefficient of the residual magnetic flux density is “good”
  • the coercive force temperature characteristics The evaluation is "good”. This indicates that the addition of the additive element N does not change the effect obtained as long as an appropriate structural morphology is formed.
  • the samples of Examples 1 to 8 are rare earth sintered magnets 1 satisfying the general formula (Nd, La, Sm)-Fe-BM and containing crystal grains based on the R 2 Fe 14 B crystal structure.
  • a main phase 10 a crystalline first subphase 21 mainly composed of an oxide phase represented by (Nd, La, Sm)-O, and an oxide phase represented by (Nd, La)-O
  • the concentration of Sm is higher in the first subphase 21 than in the second subphase 22, and the concentration of the element M is higher than that in the first subphase 22.
  • these rare earth sintered magnets 1 suppress the use of Nd and heavy rare earth elements, which are expensive, highly unevenly distributed, and have procurement risks, compared to rare earth sintered magnets that satisfy Nd--Fe--B. It is possible to improve the magnetic properties at room temperature and suppress the deterioration of the magnetic properties due to temperature rise.
  • 1 rare earth sintered magnet 10 main phase, 20 subphase, 21 first subphase, 22 second subphase, 31 crucible, 32 molten alloy, 33 tundish, 34 single roll, 35 solidified alloy, 36 tray container, 37 Rare earth magnet alloy, 100 rotor, 101 rotor core, 102 magnet insertion hole, 120 rotating machine, 130 stator, 131 teeth, 132 winding.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Inorganic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)

Abstract

La présente divulgation fournit un aimant fritté à base de terres rares (1) qui satisfait à la formule générale (Nd, La, Sm)-Fe-B-M, l'élément M étant au moins un élément choisi dans le groupe constitué par Cu, Al et Ga, et comprenant : une phase principale (10) comprenant des grains cristallins ayant basiquement une structure cristalline R2Fe14B ; une première sous-phase cristalline (21) principalement composée d'une phase oxyde représentée par (Nd, La, Sm)-O ; et une seconde sous-phase cristalline (22) principalement composée d'une phase d'oxyde représentée par (Nd, La)-O. La première sous-phase (21) a une concentration plus élevée de Sm que celle de la seconde sous-phase (22), et la seconde sous-phase (22) a une concentration supérieure d'élément M que celle de la première sous-phase (21).
PCT/JP2021/028943 2021-08-04 2021-08-04 Aimant fritté à base de terres rares, procédé de production d'un aimant fritté à base de terres rares, rotor et machine rotative WO2023012929A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
DE112021008057.1T DE112021008057T5 (de) 2021-08-04 2021-08-04 Seltenerd-sintermagnet, verfahren zum produzieren eines seltenerd-sintermagneten, rotor und rotationsmaschine
CN202180101117.7A CN117751414A (zh) 2021-08-04 2021-08-04 稀土烧结磁铁及稀土烧结磁铁的制造方法、转子以及旋转机
KR1020247002522A KR20240028440A (ko) 2021-08-04 2021-08-04 희토류 소결 자석 및 희토류 소결 자석의 제조 방법, 회전자, 및 회전기
JP2021573953A JP7130156B1 (ja) 2021-08-04 2021-08-04 希土類焼結磁石および希土類焼結磁石の製造方法、回転子並びに回転機
PCT/JP2021/028943 WO2023012929A1 (fr) 2021-08-04 2021-08-04 Aimant fritté à base de terres rares, procédé de production d'un aimant fritté à base de terres rares, rotor et machine rotative

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2021/028943 WO2023012929A1 (fr) 2021-08-04 2021-08-04 Aimant fritté à base de terres rares, procédé de production d'un aimant fritté à base de terres rares, rotor et machine rotative

Publications (1)

Publication Number Publication Date
WO2023012929A1 true WO2023012929A1 (fr) 2023-02-09

Family

ID=83148909

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/028943 WO2023012929A1 (fr) 2021-08-04 2021-08-04 Aimant fritté à base de terres rares, procédé de production d'un aimant fritté à base de terres rares, rotor et machine rotative

Country Status (5)

Country Link
JP (1) JP7130156B1 (fr)
KR (1) KR20240028440A (fr)
CN (1) CN117751414A (fr)
DE (1) DE112021008057T5 (fr)
WO (1) WO2023012929A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024042638A1 (fr) * 2022-08-24 2024-02-29 三菱電機株式会社 Aimant fritté à base de terres rares, son procédé de fabrication, rotor et machine rotative

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009302262A (ja) * 2008-06-12 2009-12-24 Toshiba Corp 永久磁石およびその製造方法
JP6359232B1 (ja) * 2017-12-05 2018-07-18 三菱電機株式会社 永久磁石、永久磁石の製造方法、および、回転機
WO2019151245A1 (fr) * 2018-01-30 2019-08-08 Tdk株式会社 Aimant permanent de terres rares à base de r-t-b
JP6692506B1 (ja) * 2019-09-10 2020-05-13 三菱電機株式会社 希土類磁石合金、その製造方法、希土類磁石、回転子及び回転機
JP2020107849A (ja) * 2018-12-28 2020-07-09 トヨタ自動車株式会社 希土類磁石及びその製造方法
JP2020155657A (ja) * 2019-03-22 2020-09-24 日立金属株式会社 Ｒ−ｔ−ｂ系焼結磁石の製造方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014086529A (ja) * 2012-10-23 2014-05-12 Toyota Motor Corp 希土類焼結磁石とその製造方法
JP6269279B2 (ja) * 2014-04-15 2018-01-31 Tdk株式会社 永久磁石およびモータ
JP2018174205A (ja) 2017-03-31 2018-11-08 大同特殊鋼株式会社 Ｒ−ｔ−ｂ系焼結磁石およびその製造方法
JP2021009862A (ja) 2017-10-18 2021-01-28 住友電気工業株式会社 希土類磁石素材

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009302262A (ja) * 2008-06-12 2009-12-24 Toshiba Corp 永久磁石およびその製造方法
JP6359232B1 (ja) * 2017-12-05 2018-07-18 三菱電機株式会社 永久磁石、永久磁石の製造方法、および、回転機
WO2019151245A1 (fr) * 2018-01-30 2019-08-08 Tdk株式会社 Aimant permanent de terres rares à base de r-t-b
JP2020107849A (ja) * 2018-12-28 2020-07-09 トヨタ自動車株式会社 希土類磁石及びその製造方法
JP2020155657A (ja) * 2019-03-22 2020-09-24 日立金属株式会社 Ｒ−ｔ−ｂ系焼結磁石の製造方法
JP6692506B1 (ja) * 2019-09-10 2020-05-13 三菱電機株式会社 希土類磁石合金、その製造方法、希土類磁石、回転子及び回転機

Also Published As

Publication number Publication date
JPWO2023012929A1 (fr) 2023-02-09
DE112021008057T5 (de) 2024-07-11
JP7130156B1 (ja) 2022-09-02
CN117751414A (zh) 2024-03-22
KR20240028440A (ko) 2024-03-05

Similar Documents

Publication Publication Date Title
JP6274216B2 (ja) Ｒ−ｔ−ｂ系焼結磁石、および、モータ
TWI673730B (zh) Ｒ－Ｆｅ－Ｂ系燒結磁石及其製造方法
JP6520789B2 (ja) Ｒ−Ｆｅ−Ｂ系焼結磁石及びその製造方法
JP6330813B2 (ja) Ｒ−ｔ−ｂ系焼結磁石、および、モータ
JP5331885B2 (ja) 永久磁石とそれを用いた可変磁束モータおよび発電機
JP6489201B2 (ja) Ｒ−ｔ−ｂ系焼結磁石の製造方法
JP6692506B1 (ja) 希土類磁石合金、その製造方法、希土類磁石、回転子及び回転機
JP2012099523A (ja) 異方性希土類焼結磁石及びその製造方法
JP7130156B1 (ja) 希土類焼結磁石および希土類焼結磁石の製造方法、回転子並びに回転機
WO2012029527A1 (fr) Alliage pour aimant permanent en terres rares à base de r-t-b, procédé de fabrication dudit aimant, et moteur
JP7214043B2 (ja) 希土類焼結磁石および希土類焼結磁石の製造方法、回転子並びに回転機
JP7254912B2 (ja) 希土類焼結磁石、希土類焼結磁石の製造方法、回転子および回転機
WO2024042638A1 (fr) Aimant fritté à base de terres rares, son procédé de fabrication, rotor et machine rotative
WO2024166148A1 (fr) Aimant fritté à base de terres rares, son procédé de fabrication, rotor et machine rotative
JP7361947B2 (ja) 希土類焼結磁石、希土類焼結磁石の製造方法、回転子および回転機
JP2020155657A (ja) Ｒ−ｔ−ｂ系焼結磁石の製造方法
JP2014209547A (ja) 希土類磁石
JP7114970B2 (ja) Ｒ－ｔ－ｂ系永久磁石
JP2004006767A (ja) 永久磁石
JP5726960B2 (ja) 永久磁石とそれを用いた可変磁束モータおよび発電機

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2021573953

Country of ref document: JP

Kind code of ref document: A

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21952756

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2301008119

Country of ref document: TH

WWE Wipo information: entry into national phase

Ref document number: 202427003633

Country of ref document: IN

ENP Entry into the national phase

Ref document number: 20247002522

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 18293355

Country of ref document: US

Ref document number: 202180101117.7

Country of ref document: CN

122 Ep: pct application non-entry in european phase

Ref document number: 21952756

Country of ref document: EP

Kind code of ref document: A1